Yes, by herself
Yes, with Isane's help
No, Kenpachi or someone else will save them
The level of all the Ritters wasn't stated.The only instance where something about their level was said was when Akon informed Ichigo of the strength of some of the Ritters.
If we assume that all the 26 Ritters were involved in the First Invasion,Then some of the 10 Ritters might not qualify to be said to be of Captain level*.I think Gwenhael belongs to that pool.He seems to be just a Clean up guy,I guess it's reasonable to think that he was sent by Yhwach to finish off Rose and Kensei.Yhwach should've got access to James' memories after his death and he should've understood that Rukia took away the badly wounded Captains.
*Akon might not have been able to determine the level of other Ritters for whatever reason but there could be more Ritters like Gwenhael who is seemingly not Captain material.
This may sound mad crazy, but what if, Yachiru is Zaraki and Unohana's baby. Just here me out, before you guys curse me with cancer or something.
Kenpachi had no memory of his past, when he found Yachiru and later took her at his side, up until he replaced the 11th division captain. I think, Unohana trained Zaraki, after their first duel and when he got older and became a man, he turned her a** out. Maybe there was dispute or something about him and Unohana having a child, because their both ruthless killers at heart and a child would carry on that bloodlust.
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